Ultra-high performance sintered NdFeB material with low oxygen content and its manufacturing method

Abstract

A sintered neodymium iron boron material with low oxygen content and a high performance and a production method thereof belong to the field of rear earth preparation. The processes of secondary smelting, deslagging, scale cinder removal, anti-oxidation powder production, one-step forming under oxygen-free and low-temperature conditions and intermittent air cooling are utilized to comprehensively and effectively control the oxygen content in the finished magnet product to be less than 800ppm. The oxygen element is turned into benefit from harm, the reasonable amount of rear-earth oxide forms pinning points on the grain boundary, consequently, the coercive force is increased, the saturated magnetization intensity of the principal phase of the magnet is greatly enhanced, meanwhile, the contents of light rear earth and heavy rear earth can be reduced, and on the basis of not adding extra processes, the cost is saved.

Description

technical field [0001] The invention belongs to the field of preparation of rare earth magnetic materials, and in particular relates to a low oxygen content ultra-high performance sintered NdFeB material and a manufacturing method thereof. Background technique [0002] Today, in the fields of electronics, information, and communication industries, the development and application speed of rare earth permanent magnet materials is at the forefront. Rare earth permanent magnet materials have also penetrated into the fields of automobiles, medical equipment, transportation, and aerospace industries, all of which provide an increasingly broad market for the development of rare earth permanent magnet materials; higher requirement. [0003] In the existing production technology of rare earth permanent magnet materials, oxygen is considered as an unfavorable element that damages the comprehensive performance of permanent magnets. Controlling oxygen content and reducing material oxid...

AI Technical Summary

Problems solved by technology

In the wet process of Hitachi Metals (Japanese Patent Laid-Open No. 11-97223), the oxygen content is distributed between 1200 and 2000 ppm, and mineral oil and deoiling processes are used. The process is cumbersome and costly, and it is difficult to realize industrialized mass production.

[0004] In the low-oxygen production process of Yantai Zhenghai Magnetic Materials Co., Ltd. in China (patent number 02158707.8), the controllable oxygen addition process based on the anaerobic process is adopted. The oxygen content is between 100 and 900 ppm. It is difficult to achieve anaerobic conditions in industrial production. Moreover, the controlled addition of oxygen in the neutralization process will cause the oxygen element to not diffuse uniformly into the magnet, causing serious oxidation of part of the magnetic powder and the degree of oxidation is inconsistent, and it is difficult to obtain a magnet with uniform distribution of oxygen content and excellent consistency.